California waste-to-energy facilities close as solar energy dominates

California's biomass energy plants are shutting down as competing, subsidized solar farms emerge, mainly in San Joaquin Valley. Six of these waste-to- energy facilities have closed in two years, including a plant in Delano, owned and operated by Covanta, after San Diego Gas & Electric terminated its power purchase agreement with the company.

Nearby, the Rio Bravo biomass facility will receive some of the fuel that would have gone to Delano, but that plant’s power purchase agreement with Pacific Gas & Electric Co. expires this year. And a Buena Vista biomass facility in Ione may lose its contract with Sacramento Municipal Utility District, according to the district’s spokesman Christopher Capra.

As a result of the plant closures, San Joaquin Valley Air Pollution Control District may allow more agricultural waste to be burned in open piles, which produces pollution and compounds tied to cardiovascular illnesses.

Some farmers are experimenting with a new technology that burns about 100 pounds of hulls per hour, though this production figure falls short of the ton per hour the largest biomass plants can handle, and the technology could take a decade to fully develop, according to industry experts.